Bulk 1-1/4"-7 Grade B Heavy Hex Bolts (A307, Coarse Thread, Zinc CR+3)

High-Strength Fasteners for Structural & Industrial Applications

For industrial and structural fastening requiring high strength, trust 1-1/4"-7 ASTM A307 Grade B Heavy Hex Bolts. These bolts are precision-engineered from low-carbon steel with a Zinc CR+3 finish for corrosion resistance and durability. Designed for flanged joints in piping systems, steel construction, and heavy equipment assembly, they provide reliable performance in demanding environments.

Note – PT = Partial Thread

Key Specifications

• Material: Low-carbon steel (ASTM A307 Grade B compliant)
• Tensile Strength: 60,000 - 100,000 psi tensile strength
• Thread Size: 1-1/4"-7 Coarse Thread (UNC)
• Finish: Zinc CR+3 for corrosion resistance (RoHS compliant)
• Head Style: Heavy hex head for superior wrench grip and strength
• Compliance: Meets ASTM A307 Grade B specifications

Why Choose Zinc CR+3 Coating?

Our Zinc CR+3 finish offers superior corrosion protection and is fully RoHS compliant, making these bolts safe for environmentally regulated applications. This coating:

• Enhances Durability: Provides a protective layer that resists rust and oxidation.
• Meets Environmental Standards: RoHS-compliant and free of hazardous hexavalent chromium.
• Improves Aesthetic Appeal: Clean and bright finish for professional applications.

Differences Between ASTM A307 Grade A & B

Understanding the differences between A307 Grade A and B is essential for selecting the right bolt for your application:

• Grade A: General-purpose fasteners for construction and industrial applications with a minimum tensile strength of 60,000 psi.
• Grade B: Specifically designed for flanged joints in piping systems with cast iron flanges, with a tensile strength of 60,000 - 100,000 psi.
• Why Choose Grade B for 1-1/4"-7 Heavy Hex Bolts? The heavy hex head design ensures a stronger and more secure hold, making it the preferred choice for high-load structural applications and piping installations.

Benefits of ASTM A307 Grade B Heavy Hex Bolts

• Increased Strength: Higher tensile range (up to 100,000 psi) for secure fastening in demanding applications.
• Reliable Flange Joint Fastener: Engineered for structural steel, bridge construction, and industrial piping.
• Heavy Hex Head: Larger head provides greater bearing surface and higher torque capability.
• Corrosion Protection: Zinc CR+3 plating prevents oxidation and extends the bolt’s service life.

Industries & Applications

• Structural Steel & Construction: Ideal for bolted connections in commercial buildings and heavy-duty frameworks.
• Piping & Flange Joints: Designed for securing cast iron flanges in industrial pipeline systems.
• Utility & Infrastructure: Used in power plants, water treatment facilities, and outdoor industrial installations.
• Heavy Equipment Assembly: Ensures a secure fit in machinery and transportation structures.

Installation Tips

• Use the Right Tools: Heavy hex head bolts require a larger wrench size for proper torque application.
• Torque Properly: Follow ASTM guidelines to achieve correct tightness without overloading the bolt.
• Pair with Compatible Hardware: Use with heavy hex nuts and washers for maximum stability and security.
• Store in Dry Conditions: Protect bolts from excess moisture before installation to maintain finish integrity.

Bulk Purchasing Advantages

• Cost Savings: Bulk purchases reduce per-unit cost, making large projects more economical.
• Consistent Product Quality: All bulk orders come from the same production lot to ensure uniformity.
• Reliable Supply: Maintain project timelines with readily available stock.
• Designed for Professionals: Perfect for contractors, manufacturers, and industrial suppliers handling large-scale construction and infrastructure projects.

Order in Bulk & Save

Ensure your project is built to last with bulk 1-1/4"-7 ASTM A307 Grade B Heavy Hex Bolts. Engineered for structural steel connections, flange joints, and high-load industrial applications. Order now for bulk discounts, fast shipping, and top-rated customer support.

✔️ Best for structural, piping, and industrial projects

✔️ Heavy hex head design for high-load applications

✔️ ASTM A307 Grade B compliant with Zinc CR+3 (RoHS) finish